shorten frames to closure vars only on gc

mcode.cm

@@ -951,6 +951,7 @@ var mcode = function(ast) {
   }
 
   // Scan scope record for variable declarations
+  // Closure locals are assigned first so returned frames can be shortened
   var scan_scope = function() {
     var scope = find_scope_record(s_function_nr)
     if (scope == null) {
@@ -963,6 +964,9 @@ var mcode = function(ast) {
     var make = null
     var is_const = false
     var slot = 0
+
+    // Pass 1: closure locals first
+    _i = 0
     while (_i < length(keys)) {
       name = keys[_i]
       if (name == "function_nr" || name == "nr_close_slots") {
@@ -975,14 +979,36 @@ var mcode = function(ast) {
         _i = _i + 1
         continue
       }
-      if (find_var(name) < 0) {
+      if (v.closure == true && find_var(name) < 0) {
+        is_const = (make == "def" || make == "function")
+        slot = 1 + s_nr_args + s_nr_local_slots
+        s_nr_local_slots = s_nr_local_slots + 1
+        s_nr_close_slots = s_nr_close_slots + 1
+        add_var(name, slot, is_const)
+        s_vars[length(s_vars) - 1].is_closure = true
+      }
+      _i = _i + 1
+    }
+
+    // Pass 2: non-closure locals
+    _i = 0
+    while (_i < length(keys)) {
+      name = keys[_i]
+      if (name == "function_nr" || name == "nr_close_slots") {
+        _i = _i + 1
+        continue
+      }
+      v = scope[name]
+      make = v.make
+      if (make == null || make == "input") {
+        _i = _i + 1
+        continue
+      }
+      if (v.closure != true && find_var(name) < 0) {
         is_const = (make == "def" || make == "function")
         slot = 1 + s_nr_args + s_nr_local_slots
         s_nr_local_slots = s_nr_local_slots + 1
         add_var(name, slot, is_const)
-        if (v.closure == true) {
-          s_vars[length(s_vars) - 1].is_closure = true
-        }
       }
       _i = _i + 1
     }
@@ -2738,8 +2764,6 @@ var mcode = function(ast) {
     var disrupt_clause = func_node.disruption
     var null_slot2 = null
     var fn_name = func_node.name
-    var fn_scope = null
-    var nr_cs = 0
     var result = null
     var saved_label = 0
     var saved_func = 0
@@ -2880,15 +2904,10 @@ var mcode = function(ast) {
       fn_name = "<anonymous>"
     }
 
-    fn_scope = find_scope_record(s_function_nr)
-    if (fn_scope != null && fn_scope.nr_close_slots != null) {
-      nr_cs = fn_scope.nr_close_slots
-    }
-
     result = {
       name: fn_name,
       nr_args: nr_params,
-      nr_close_slots: nr_cs,
+      nr_close_slots: s_nr_close_slots,
       nr_slots: s_max_slot + 1,
       disruption_pc: disruption_start,
       instructions: s_instructions